1. Field of the Invention
The present invention relates generally to fiber optic connector assemblies, and more specifically, to fiber optic connector assemblies with a field-installable crimp-on boot and an O-ring on a plug assembly for interconnecting optical fibers within a fiber optic communications network.
2. Technical Background of the Invention
Optical fiber is increasingly being used for a variety of broadband applications including voice, video and data transmissions. As a result of the desire to expand telecommunications networks, larger networks require a greater number of distribution cables, drop cables, assemblies and connecting hardware. One example of connecting hardware includes plug assemblies, also referred to herein as “connector assemblies”, which are used to connect optical fibers through receptacles, optical devices, hardware or other plugs. Plug assemblies typically comprise the hardware mounted upon the end of a fiber optic drop cable and typically include at least one ferrule mounted upon the ends of one or more optical fibers for presenting the one or more fibers for optical connection with other optical fibers.
In addition to the foregoing, certain requirements have been established for connector assemblies and the like. Specifically, GR-3120-CORE, Issue 1, March 2005, Generic Requirements for Hardened Fiber Optic Connectors (HFOCs), issued by Telcordia Technologies, Inc. of Piscataway, N.J., contains requirements for connectors that are field-mateable and hardened (also known as ruggerdized) for use in the outside plant. These requirements are needed to support FTTx deployment and service offerings. GR-3120-CORE includes generic requirements for HFOCs for passive telecommunications components used in an Outside Plant (OSP) environment. HFOCs provide drop connections to customers from fiber distribution networks, such as FTTx, and may be provided in pedestal closures, aerial and buried closures, or equipment located at a customer premises, such as a Fiber Distribution Hub (FDH) or optical network termination unit. Through the GR-3120-CORE specifications, HFOCs are specified to withstand climatic conditions including ambient temperatures ranging from −40° C. (−40° F.) to +70° C. (158° F.).
To meet the demanding GR-3120-CORE specifications, smaller conventional connector assembly packages are needed by network providers. These connector assembly packages typically include an overmolded boot, glue body based solution or a heat shrink seal. The heat shrink seal has increased cost and is not as robust as an overmolded boot. Overmolded boots are known in the art for sealing the rear end of the plug housing and for providing strain relief. For example, the plug assembly can include a high-pressure overmolded boot made of a flexible (e.g., silicone-type or the like) material secured over a rear portion of the plug assembly and a portion of the drop cable in order to seal the exposed portion of the drop cable while generally inhibiting kinking and providing bending strain relief to the drop cable near the plug. A glue body material is injected between a buffer tube and a crimp body, but leakage occurs due to shrinkage of the material. Additionally, the overmolded boot material is very stiff to meet the GR-3120-CORE side load requirement, thus the overmolded boot material melt temperatures are high, resulting in damage to the buffer tube further complicating sealing when the overmolded boot, crimp body, and buffer tube are heated to form a seal.
The overmolded boot, crimp body, and the like provide a robust mechanical and seal integrity performance for the connector assembly to meet the GR-3120-CORE specifications in a smaller connector assembly. These solutions are provided in factory assembly. However, these solutions are not simple to execute in a typical cable assembly house or in the field. What is needed, therefore, is a simpler hardware package that can be assembled with ordinary connectorization tools. It would also be desirable to provide a simpler hardware package for a fiber optic connector and plug assembly which meets the demanding GR-3120-CORE specification. Such fiber optic connector and plug assemblies would desirably be provided with a crimp on pre-molded boot and O-ring between a buffer tube on a drop cable and a crimp body in the plug assembly.